1. Field of the Invention
The agent of this invention protects poultry from coccidiosis and benefits ruminants.
Coccidiosis is a well-known protozoan disease resulting from infection by one or more species of Eimeria or Isospora (for a summary, see Lund and Farr in "Diseases of Poultry" 5th ed., Biester and Schwarte, Eds., Iowa State University Press, Ames, Ia., pp 1056-1096). In view of the great economic losses from coccidiosis, the search for better anticoccidial agents continues.
Because ruminants are animals of economic importance, increasing ruminant feed-utilization efficiency is very desirable. The mechanism for utilization of the major nutritive portion (carbohydrates) of ruminant feed is well known. Microorganisms in the rumen of the animal ferment carbohydrates to produce monosaccharides and then degrade these monosaccharides to pyruvate compounds. Pyruvates are metabolized by microbiological processes to form acetates, butyrates or propionates, collectively known as volatile fatty acids (VFA). For a more detailed discussion, see Leng in "Physiology of Digestion and Metabolism in the Ruminant," Phillipson et al., Ed., Oriel Press, pp 408-410.
The relative efficiency of utilization of the VFA's is discussed by McCullough, Feedstuffs, June 19, 1971, page 19; Eskeland et al., Feedstuffs An. Sci. 33, 282 (1971); and Church et al., "Digestive Physiology and Nutrition of Ruminants," Vol. 2, 1971, pp 622 and 625. Although acetates and butyrates are utilized, propionates are utilized with relatively better efficiency. Furthermore, when too little propionate is available, animals may develop ketosis. A beneficial drug, therefore, encourages animals to produce propionates from carbohydrates, thereby increasing carbohydrate-utilization efficiency and also reducing the incidence of ketosis.
2. The Prior Art
Monensin, from which metabolite A-27106 can be prepared, was disclosed in U.S. Pat. No. 3,501,568 as factor A of antibiotic A3823 complex. Monensin is also an anticoccidial agent.